Answer, d' = 1118 meters
Explanation:
Given that,
The stone is thrown straight down from the edge of a roof, h = 1200 ft
Speed of the stone, u = 9 ft/s
The acceleration due to gravity is, [tex]a=-32\ ft/s^2[/tex]
Time, t = 2 s
Let d is height reached by the stone in 2 seconds. It can be calculated using second equation of motion as :
[tex]d=ut+\dfrac{1}{2}at^2[/tex]
Here, a = g
[tex]d=ut+\dfrac{1}{2}gt^2[/tex]
[tex]d=9\times 2+\dfrac{1}{2}\times 32\times 2^2[/tex]
d = 82 m
So, the height of stone after 2 seconds is,
d' = 1200 - 82
d' = 1118 meters
Hence, this is the required solution.
